4 files changed, 87 insertions, 46 deletions

diff --git a/drivers/infiniband/core/core_priv.h b/drivers/infiniband/core/core_priv.h
index 888d89ce81df..beee7b7e0d9a 100644
--- a/drivers/infiniband/core/core_priv.h
+++ b/drivers/infiniband/core/core_priv.h
@@ -302,7 +302,9 @@ static inline struct ib_qp *_ib_create_qp(struct ib_device *dev,
 					  struct ib_udata *udata,
 					  struct ib_uobject *uobj)
 {
+	enum ib_qp_type qp_type = attr->qp_type;
 	struct ib_qp *qp;
+	bool is_xrc;
 
 	if (!dev->ops.create_qp)
 		return ERR_PTR(-EOPNOTSUPP);
@@ -320,7 +322,8 @@ static inline struct ib_qp *_ib_create_qp(struct ib_device *dev,
 	 * and more importantly they are created internaly by driver,
 	 * see mlx5 create_dev_resources() as an example.
 	 */
-	if (attr->qp_type < IB_QPT_XRC_INI) {
+	is_xrc = qp_type == IB_QPT_XRC_INI || qp_type == IB_QPT_XRC_TGT;
+	if ((qp_type < IB_QPT_MAX && !is_xrc) || qp_type == IB_QPT_DRIVER) {
 		qp->res.type = RDMA_RESTRACK_QP;
 		if (uobj)
 			rdma_restrack_uadd(&qp->res);
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 9773145dee09..ea8661a00651 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -94,11 +94,17 @@ static DEFINE_XARRAY_FLAGS(devices, XA_FLAGS_ALLOC);
 static DECLARE_RWSEM(devices_rwsem);
 #define DEVICE_REGISTERED XA_MARK_1
 
-static LIST_HEAD(client_list);
+static u32 highest_client_id;
 #define CLIENT_REGISTERED XA_MARK_1
 static DEFINE_XARRAY_FLAGS(clients, XA_FLAGS_ALLOC);
 static DECLARE_RWSEM(clients_rwsem);
 
+static void ib_client_put(struct ib_client *client)
+{
+	if (refcount_dec_and_test(&client->uses))
+		complete(&client->uses_zero);
+}
+
 /*
  * If client_data is registered then the corresponding client must also still
  * be registered.
@@ -661,6 +667,14 @@ static int add_client_context(struct ib_device *device,
 
 	down_write(&device->client_data_rwsem);
 	/*
+	 * So long as the client is registered hold both the client and device
+	 * unregistration locks.
+	 */
+	if (!refcount_inc_not_zero(&client->uses))
+		goto out_unlock;
+	refcount_inc(&device->refcount);
+
+	/*
 	 * Another caller to add_client_context got here first and has already
 	 * completely initialized context.
 	 */
@@ -683,6 +697,9 @@ static int add_client_context(struct ib_device *device,
 	return 0;
 
 out:
+	ib_device_put(device);
+	ib_client_put(client);
+out_unlock:
 	up_write(&device->client_data_rwsem);
 	return ret;
 }
@@ -702,7 +719,7 @@ static void remove_client_context(struct ib_device *device,
 	client_data = xa_load(&device->client_data, client_id);
 	xa_clear_mark(&device->client_data, client_id, CLIENT_DATA_REGISTERED);
 	client = xa_load(&clients, client_id);
-	downgrade_write(&device->client_data_rwsem);
+	up_write(&device->client_data_rwsem);
 
 	/*
 	 * Notice we cannot be holding any exclusive locks when calling the
@@ -712,17 +729,13 @@ static void remove_client_context(struct ib_device *device,
 	 *
 	 * For this reason clients and drivers should not call the
 	 * unregistration functions will holdling any locks.
-	 *
-	 * It tempting to drop the client_data_rwsem too, but this is required
-	 * to ensure that unregister_client does not return until all clients
-	 * are completely unregistered, which is required to avoid module
-	 * unloading races.
 	 */
 	if (client->remove)
 		client->remove(device, client_data);
 
 	xa_erase(&device->client_data, client_id);
-	up_read(&device->client_data_rwsem);
+	ib_device_put(device);
+	ib_client_put(client);
 }
 
 static int alloc_port_data(struct ib_device *device)
@@ -1224,7 +1237,7 @@ static int setup_device(struct ib_device *device)
 
 static void disable_device(struct ib_device *device)
 {
-	struct ib_client *client;
+	u32 cid;
 
 	WARN_ON(!refcount_read(&device->refcount));
 
@@ -1232,10 +1245,19 @@ static void disable_device(struct ib_device *device)
 	xa_clear_mark(&devices, device->index, DEVICE_REGISTERED);
 	up_write(&devices_rwsem);
 
+	/*
+	 * Remove clients in LIFO order, see assign_client_id. This could be
+	 * more efficient if xarray learns to reverse iterate. Since no new
+	 * clients can be added to this ib_device past this point we only need
+	 * the maximum possible client_id value here.
+	 */
 	down_read(&clients_rwsem);
-	list_for_each_entry_reverse(client, &client_list, list)
-		remove_client_context(device, client->client_id);
+	cid = highest_client_id;
 	up_read(&clients_rwsem);
+	while (cid) {
+		cid--;
+		remove_client_context(device, cid);
+	}
 
 	/* Pairs with refcount_set in enable_device */
 	ib_device_put(device);
@@ -1662,30 +1684,31 @@ static int assign_client_id(struct ib_client *client)
 	/*
 	 * The add/remove callbacks must be called in FIFO/LIFO order. To
 	 * achieve this we assign client_ids so they are sorted in
-	 * registration order, and retain a linked list we can reverse iterate
-	 * to get the LIFO order. The extra linked list can go away if xarray
-	 * learns to reverse iterate.
+	 * registration order.
 	 */
-	if (list_empty(&client_list)) {
-		client->client_id = 0;
-	} else {
-		struct ib_client *last;
-
-		last = list_last_entry(&client_list, struct ib_client, list);
-		client->client_id = last->client_id + 1;
-	}
+	client->client_id = highest_client_id;
 	ret = xa_insert(&clients, client->client_id, client, GFP_KERNEL);
 	if (ret)
 		goto out;
 
+	highest_client_id++;
 	xa_set_mark(&clients, client->client_id, CLIENT_REGISTERED);
-	list_add_tail(&client->list, &client_list);
 
 out:
 	up_write(&clients_rwsem);
 	return ret;
 }
 
+static void remove_client_id(struct ib_client *client)
+{
+	down_write(&clients_rwsem);
+	xa_erase(&clients, client->client_id);
+	for (; highest_client_id; highest_client_id--)
+		if (xa_load(&clients, highest_client_id - 1))
+			break;
+	up_write(&clients_rwsem);
+}
+
 /**
  * ib_register_client - Register an IB client
  * @client:Client to register
@@ -1705,6 +1728,8 @@ int ib_register_client(struct ib_client *client)
 	unsigned long index;
 	int ret;
 
+	refcount_set(&client->uses, 1);
+	init_completion(&client->uses_zero);
 	ret = assign_client_id(client);
 	if (ret)
 		return ret;
@@ -1740,21 +1765,30 @@ void ib_unregister_client(struct ib_client *client)
 	unsigned long index;
 
 	down_write(&clients_rwsem);
+	ib_client_put(client);
 	xa_clear_mark(&clients, client->client_id, CLIENT_REGISTERED);
 	up_write(&clients_rwsem);
-	/*
-	 * Every device still known must be serialized to make sure we are
-	 * done with the client callbacks before we return.
-	 */
-	down_read(&devices_rwsem);
-	xa_for_each (&devices, index, device)
+
+	/* We do not want to have locks while calling client->remove() */
+	rcu_read_lock();
+	xa_for_each (&devices, index, device) {
+		if (!ib_device_try_get(device))
+			continue;
+		rcu_read_unlock();
+
 		remove_client_context(device, client->client_id);
-	up_read(&devices_rwsem);
 
-	down_write(&clients_rwsem);
-	list_del(&client->list);
-	xa_erase(&clients, client->client_id);
-	up_write(&clients_rwsem);
+		ib_device_put(device);
+		rcu_read_lock();
+	}
+	rcu_read_unlock();
+
+	/*
+	 * remove_client_context() is not a fence, it can return even though a
+	 * removal is ongoing. Wait until all removals are completed.
+	 */
+	wait_for_completion(&client->uses_zero);
+	remove_client_id(client);
 }
 EXPORT_SYMBOL(ib_unregister_client);
 
diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index cc99479b2c09..9947d16edef2 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -3224,18 +3224,18 @@ static int ib_mad_port_open(struct ib_device *device,
 	if (has_smi)
 		cq_size *= 2;
 
+	port_priv->pd = ib_alloc_pd(device, 0);
+	if (IS_ERR(port_priv->pd)) {
+		dev_err(&device->dev, "Couldn't create ib_mad PD\n");
+		ret = PTR_ERR(port_priv->pd);
+		goto error3;
+	}
+
 	port_priv->cq = ib_alloc_cq(port_priv->device, port_priv, cq_size, 0,
 			IB_POLL_UNBOUND_WORKQUEUE);
 	if (IS_ERR(port_priv->cq)) {
 		dev_err(&device->dev, "Couldn't create ib_mad CQ\n");
 		ret = PTR_ERR(port_priv->cq);
-		goto error3;
-	}
-
-	port_priv->pd = ib_alloc_pd(device, 0);
-	if (IS_ERR(port_priv->pd)) {
-		dev_err(&device->dev, "Couldn't create ib_mad PD\n");
-		ret = PTR_ERR(port_priv->pd);
 		goto error4;
 	}
 
@@ -3278,11 +3278,11 @@ error8:
 error7:
 	destroy_mad_qp(&port_priv->qp_info[0]);
 error6:
-	ib_dealloc_pd(port_priv->pd);
-error4:
 	ib_free_cq(port_priv->cq);
 	cleanup_recv_queue(&port_priv->qp_info[1]);
 	cleanup_recv_queue(&port_priv->qp_info[0]);
+error4:
+	ib_dealloc_pd(port_priv->pd);
 error3:
 	kfree(port_priv);
 
@@ -3312,8 +3312,8 @@ static int ib_mad_port_close(struct ib_device *device, int port_num)
 	destroy_workqueue(port_priv->wq);
 	destroy_mad_qp(&port_priv->qp_info[1]);
 	destroy_mad_qp(&port_priv->qp_info[0]);
-	ib_dealloc_pd(port_priv->pd);
 	ib_free_cq(port_priv->cq);
+	ib_dealloc_pd(port_priv->pd);
 	cleanup_recv_queue(&port_priv->qp_info[1]);
 	cleanup_recv_queue(&port_priv->qp_info[0]);
 	/* XXX: Handle deallocation of MAD registration tables */
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 9f8a48016b41..ffdeaf6e0b68 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -49,6 +49,7 @@
 #include <linux/sched.h>
 #include <linux/semaphore.h>
 #include <linux/slab.h>
+#include <linux/nospec.h>
 
 #include <linux/uaccess.h>
 
@@ -884,11 +885,14 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, u32 __user *arg)
 
 	if (get_user(id, arg))
 		return -EFAULT;
+	if (id >= IB_UMAD_MAX_AGENTS)
+		return -EINVAL;
 
 	mutex_lock(&file->port->file_mutex);
 	mutex_lock(&file->mutex);
 
-	if (id >= IB_UMAD_MAX_AGENTS || !__get_agent(file, id)) {
+	id = array_index_nospec(id, IB_UMAD_MAX_AGENTS);
+	if (!__get_agent(file, id)) {
 		ret = -EINVAL;
 		goto out;
 	}